/* This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 * 02111-1307, USA.
 *
 * http://www.gnu.org/copyleft/gpl.html
 */
package com.l2jfrozen.gameserver.model;

import javolution.util.FastList;

import com.l2jfrozen.Config;
import com.l2jfrozen.util.random.Rnd;

/**
 * @author Fulminus
 */
public class L2DropCategory
{
	private FastList<L2DropData> _drops;
	private int _categoryChance; // a sum of chances for calculating if an item will be dropped from this category
	private int _categoryBalancedChance; // sum for balancing drop selection inside categories in high rate servers
	private int _categoryType;

	public L2DropCategory(int categoryType)
	{
		_categoryType = categoryType;
		_drops = new FastList<L2DropData>(0);
		_categoryChance = 0;
		_categoryBalancedChance = 0;
	}

	public void addDropData(L2DropData drop, boolean raid)
	{
		if(drop.isQuestDrop())
		{
			//			if (_questDrops == null)
			//				_questDrops = new FastList<L2DropData>(0);
			//	        _questDrops.add(drop);
		}
		else
		{
			_drops.add(drop);
			_categoryChance += drop.getChance();
			// for drop selection inside a category: max 100 % chance for getting an item, scaling all values to that.
			_categoryBalancedChance += Math.min((drop.getChance() * (raid ? 1 : Config.RATE_DROP_ITEMS)), L2DropData.MAX_CHANCE);
		}
	}

	public FastList<L2DropData> getAllDrops()
	{
		return _drops;
	}

	public void clearAllDrops()
	{
		_drops.clear();
	}

	public boolean isSweep()
	{
		return getCategoryType() == -1;
	}

	// this returns the chance for the category to be visited in order to check if
	// drops might come from it.  Category -1 (spoil) must always be visited
	// (but may return 0 or many drops)
	public int getCategoryChance()
	{
		if(getCategoryType() >= 0)
			return _categoryChance;
		return L2DropData.MAX_CHANCE;
	}

	public int getCategoryBalancedChance()
	{
		if(getCategoryType() >= 0)
			return _categoryBalancedChance;
		return L2DropData.MAX_CHANCE;
	}

	public int getCategoryType()
	{
		return _categoryType;
	}

	/**
	 * useful for seeded conditions...the category will attempt to drop only among items that are allowed to be dropped
	 * when a mob is seeded. Previously, this only included adena. According to sh1ny, sealstones are also acceptable
	 * drops. if no acceptable drops are in the category, nothing will be dropped. otherwise, it will check for the
	 * item's chance to drop and either drop it or drop nothing.
	 * 
	 * @return acceptable drop when mob is seeded, if it exists. Null otherwise.
	 */
	public synchronized L2DropData dropSeedAllowedDropsOnly()
	{
		FastList<L2DropData> drops = new FastList<L2DropData>();
		int subCatChance = 0;
		for(L2DropData drop : getAllDrops())
		{
			if(drop.getItemId() == 57 || drop.getItemId() == 6360 || drop.getItemId() == 6361 || drop.getItemId() == 6362)
			{
				drops.add(drop);
				subCatChance += drop.getChance();
			}
		}

		// among the results choose one.
		int randomIndex = Rnd.get(subCatChance);
		int sum = 0;
		for(L2DropData drop : drops)
		{
			sum += drop.getChance();

			if(sum > randomIndex) // drop this item and exit the function
			{
				drops.clear();
				drops = null;
				return drop;
			}
		}

		drops = null;

		// since it is still within category, only drop one of the acceptable drops from the results.
		return null;
	}

	/**
	 * ONE of the drops in this category is to be dropped now. to see which one will be dropped, weight all items'
	 * chances such that their sum of chances equals MAX_CHANCE. since the individual drops have their base chance, we
	 * also ought to use the base category chance for the weight. So weight = MAX_CHANCE/basecategoryDropChance. Then
	 * get a single random number within this range. The first item (in order of the list) whose contribution to the sum
	 * makes the sum greater than the random number, will be dropped. Edited: How _categoryBalancedChance works in high
	 * rate servers: Let's say item1 has a drop chance (when considered alone, without category) of 1 % *
	 * RATE_DROP_ITEMS and item2 has 20 % * RATE_DROP_ITEMS, and the server's RATE_DROP_ITEMS is for example 50x.
	 * Without this balancer, the relative chance inside the category to select item1 to be dropped would be 1/26 and
	 * item2 25/26, no matter what rates are used. In high rate servers people usually consider the 1 % individual drop
	 * chance should become higher than this relative chance (1/26) inside the category, since having the both items for
	 * example in their own categories would result in having a drop chance for item1 50 % and item2 1000 %.
	 * _categoryBalancedChance limits the individual chances to 100 % max, making the chance for item1 to be selected
	 * from this category 50/(50+100) = 1/3 and item2 100/150 = 2/3. This change doesn't affect calculation when
	 * drop_chance * RATE_DROP_ITEMS < 100 %, meaning there are no big changes for low rate servers and no changes at
	 * all for 1x servers.
	 * @param raid 
	 * @return selected drop from category, or null if nothing is dropped.
	 */
	public synchronized L2DropData dropOne(boolean raid)
	{
		int randomIndex = Rnd.get(getCategoryBalancedChance());
		int sum = 0;
		for(L2DropData drop : getAllDrops())
		{
			sum += Math.min((drop.getChance() * (raid ? 1 : Config.RATE_DROP_ITEMS)), L2DropData.MAX_CHANCE);

			if(sum >= randomIndex) // drop this item and exit the function
				return drop;
		}
		return null;
	}
}
